The early Christians were quick to spot new heresies. In the third century, Sabellius, a Libyan priest who was staying at Rome, invented a new one. He claimed there is only one person in the Godhead, so that the Father, the Son, and the Holy Spirit are all one person with different "offices," rather than three persons who are one being in the Godhead, as the orthodox position holds.

Of course, people immediately recognized that Sabellius’s teaching contradicted the historic faith of the Church, and he was quickly excommunicated. His heresy became known as Sabellianism, Modalism, and Patripassianism. It was called Sabellianism after its founder, Modalism after the three modes or roles which it claimed the one person of the Trinity occupied, and Patripassianism after its implication that the person of the Father (Pater-) suffered (-passion) on the cross when Jesus died.

In this tract we see that the Fathers’ forceful rejection of Modalism is shown not only when they condemn it by name, but also by passages in which they speak of one person of the Trinity being with another, being sent from another, or speaking to another.